YMMV / Junkworld

• Demonic Spiders:
  • Brutalizers, the Wasteland denizen. While slow, he is tough and hits hard, but his main danger is a Draw Aggro that forces all towers and tactics to attack him instead of other enemies that can safely run past and cause leakages. This is especially obvious when those enemies are Motorcycles or Smoke Runners.
  • Gator Riders, the Giant Mook enemies of the Swamps. They have tons of HP, and while they're slow, they sport a very painful ranged attack from the rider's shotgun. Attempt to block them in melee combat is not effective as the gators hit hard and often use a One-Hit Kill bite attack to wipe out any offending troops. All this unit-killing ability allows weaker but gregarious enemies like Radcoons to leak through. The kicker is that Gator Riders appear in relatively large numbers for giant enemy standards which means that the slow-firing Snipers will have trouble taking them down quickly enough, and often appear with Radcoons to rush through your weakened defenses. Even worse? The Order levels have cyborg versions of Gator Riders with even more health and more powerful attacks.
  • Scrap Recyclers. Initially, they're not exactly notable in terms of stats, but should they absorb enough junk left behind by dead Rubble Things, they become much more dangerous and powerful Scrap Destroyers. Considering the great numbers of Rubble Things that can come out or be dropped by Urban Stompers, Recyclers have a lot of opportunities to evolve into a stronger form.
  • Urban Stompers are powerful bulldozer constructs that exclusively use a powerful area attack and come in great numbers. On death, they drop two Rubble Things that can give Scrap Recyclers even more opportunities to activate their ability.
  • Order Elite, a Killer Robot with a versatile arsenal. Not only is his melee attack painful, he has a net launcher that allows him to remove units from combat and a pair of rocket launchers that have an enormous range and are as painful. Combine that with great numbers, high health and additional shield layered on top and you get yourself one of the most dangerous Order units.
  • Vermincharges in the Underground campaign are Rat Men pushing a mortar that regularly fires capsules containing three fast-but-weak Krittlings at a spot further down the path. They come in decent enough numbers where if you don't kill them fast enough, you will be overrun by the Swarm of Rats spawned by their mortars. Finally, unlike Junkworld's sister series Kingdom Rush where blocking mooks with troops prevents them from using their ranged special abilities, Vermincharges can still fire their rat swarms even while being blocked.
  • Gutterballs in the Underground campaign are Krittlings rolling on a huge spiked metal ball. They have a ton of armored health but low HP, move very quickly, and cannot be blocked or slowed by your troops, instead just running through them for damage. The fun doesn't end when they die, for the ball releases three Krittlings which can run past to the exit if you lack firepower or defenses.
  • Frenzy Vermins may be unimpressive to some, but when other enemy dies near them, they become overwhelmed with rage and turn into Berserker Vermin, much quicker and stronger than before. It is temporary, but they can maul a lot of soldiers while it lasts.
  • Screechsnout and Duskgazer combo. The first stuns towers, the second stuns units. Bring these two together and the Kritt army is unstoppable.
• Goddamned Bats:
  • Vehicle units from the Wasteland. All 3 are unblockable, Motorcycles can speed past your defenses, Smoke Runner can make towers miss and Junk Carrier buffs other units with extra health. All 3 are somewhat easy to kill, but they can be reasons for leakings and life losses where you might not expect.
  • Wasteland Rat and it's counterparts are like Worgs, quick but squishy, but even they can slip through if you're distracted by other foes. Krittlings crank it to eleven due to not only having these traits, but also being mass produced by Vermincharges and Gutterballs, Underground's Demonic Spiders.
  • Bloating Frogs. Action Bomb at its finest, they explode, dealing area damage and leaving behind damaging sludge. They can be killed well before they reach your units, but can be of annoyance should they do.
  • Order Scientist. He might be a simple melee attacker, but he can launch syringes to give his allies regeneration and damage buff, really upping the ante if left unchecked.
  • Rubble Thing. They come in great numbers and may be killed relatively easily, leaving behind a floating junk piece that will turn back into a Rubble Thing. These junk pieces, however, are a key to Scrap Recyclers evolving into a stronger form, allowing them many chances to do so.
  • Flying Sentinel may be squishy flier, but if it reaches any of your towers, it will envelop them in electrified tentacles and temporarily remove them from combat. Especially dangerous when the other dangerous foes are also present.
  • Order Ghosts. They have invisibility cloaking device that makes them untargetable, great melee damage and micro grenades, allowing them to greatly disrupt your choke points.
  • Order Scouts, big time. For a weak flying enemy, they only appear in late levels of final world, but for a good reason. They may be weak in health, but the second they spot any Scavenger, they send an alert for backup and two Order Juggernauts drop in to wreck your defense. And they can keep doing it as long as they encounter Scavengers, flooding your defense with hulking brutes.
  • Diggarz. Imagine that Quarry Worker from Vengeance, but stronger and with more underground time. You need to counter them fast if you want those three stars.
  • Whiskeletons. They're not that hard to kill, but they can suddenly appear in the middle of the path or even past your defenses, and in great numbers too. Exemplified in final battle where they spawn en masse from the graveyard whenever your unit dies.
  • Screechsnouts and Darkgazers are literal case. They stun towers and enemies respectively, being a much more annoying version of Screecher Bat from Kingdom Rush.